During the 2016 Democratic presidential primary race, many fans of Bernie Sanders would have likely considered jumping off of a cliff if the boisterous senator asked them to. But they aren't so sure about his latest message: Get behind Hillary Clinton.

Sanders left no doubt that he's backing Clinton, his former rival, in a speech at the Democratic National Convention on Monday.

"Hillary Clinton will make an outstanding president and I am proud to stand with her tonight," Sanders told a crowd full of adoring fans still clutching Sanders' campaign signs weeks after he folded up his bid to become the Democratic nominee.

"I wish he would continue fighting," said Sanders supporter Nick Vaidyanathan at a rally Tuesday in Philadelphia. "I wish we could go all the way through a contested convention."

Sanders has made every indication that he's done fighting Clinton and the Democratic establishment. On Monday, he sent a text message to his supporters
urging them not to protest on the DNC floor. The endorsement speech
he gave that evening was perhaps the final nail in the coffin of the so-called "Bernie or Bust" movement.

At least one high-profile Sanders backer, Oscar-winning actor Susan Sarandon, was visibly displeased with the senator's unification message. "So now it's up to [Clinton]. Don't blame [Sanders] if she loses," Sarandon tweeted
on Tuesday.

Many Democrats breathed a sigh of relief after Sanders threw his full support behind Clinton on Monday.

"Democracy is noisy and I suspect that the convention will continue to be noisy but I think we are coming together," said Sen. Tammy Baldwin (D-Wisconsin) on Tuesday. The noise she was referring to came on the convention floor Monday as some Sanders supporters heckled speakers
and started several negative chants.

While the Republican party has its own unity issue behind nominee Donald Trump, some political experts feel the Democrats have a bigger problem in getting Sanders' considerable fan base to rally behind Clinton.

"The Sanders people are a larger portion of the Democratic base than the "Never Trump" people are now in the Republican race," said Dr. Susan MacManus of the University of South Florida on Tuesday.